Abstract

The adsorption site of pyridine (C5H5N) on Ni{111} has been investigated by scanned-energy mode photoelectron diffraction using the N1s core level. It was found that the nitrogen atom adsorbs close to the atop position with an angle of 18 degrees(+2 degrees/-4 degrees) between the N-Ni bond and the surface normal. The N-Ni bond length is 1.97 +/- 0.03 Angstrom. Since recent X-ray absorption studies show that the pi system of the pyridine is also tilted by about 20 degrees away from the surface normal, we conclude that the N-Ni bond and the ring plane are co-planar.